Printing of version documents is well known in the graphic arts industry. A version document is one that has some content that varies by audience. For example, printing different versions of a magazine could involve varying (altering or substituting) content for different audiences based on economic, demographic, linguistic or other differences.
An image of a specific version (e.g. a selection of common and at least one variant's content) of a version document can be produced using a variety of methods that include three main activities. First, one or more artwork documents are produced that include the common and variant content. Then, the artwork design is converted to a printable format (e.g. Adobe® PostScript® or Adobe® PDF) in a version document. Finally, an image for a specific version is produced from the version document. A version document can include one or more files or streams of data corresponding to different compositions of the printable common and variant content.
A creative design software application, exemplified by Adobe® Illustrator® or QuarkXPress™, can be used by a creative artist to develop the common and variant content in an artwork document. This can include producing separate artwork document files for each specific version wherein the variant content is modified in each file. Alternatively, one layered artwork document can be produced with common content defined on one layer and variant content defined on one or more layers. As another alternative, variant content can, in some creative applications, be defined with attributes to distinguish it from other content in the same file. For instance, an artist can define variant content using color aliases (e.g. Black-English to represent English-specific content painting in black ink).
Producing a version document by converting an artwork design to a printable format can be accomplished by converter software associated with a print function incorporated in the creative design software application or it can be performed by an external software application that operates on a format produced by the creative design software application. For exemplary printable formats such as Adobe® PostScript® and Adobe® PDF, printable elements are generated with a painting order based on a painting order defined by artwork elements of the artwork document. Painting order in an artwork document can be based on an order defined by the artist, either implicitly by the order in which artwork elements were created, or explicitly by specific ordering actions (e.g. bring to front) applied to artwork elements. In addition, artwork elements defined for a layer can have a relative order with respect to artwork elements defined for another layer (e.g. elements of a first layer paint before elements of a second layer).
Problems often occur during the version document production process and subsequent image production process whereby an image for a specific version produced is inconsistent with the artist's intent. This can occur if the artist does not understand or consider how the artwork content, especially the variant content, will be converted to a printable format (e.g. version document) or if the artist does not understand or consider how the processing of the version document to produce an image for a specific version occurs. An unintended result of processing may be undesirable (e.g. a significant color variation) or may be acceptable (e.g. a minor color variation). Thus there is a need to determine whether variant content could have an unintended, and in particular, undesirable impact on a rendered image produced by processing the version document.
Prior art methods of processing version documents often use a raster workflow. Rendering high-resolution image data for specific versions could occur relatively early in a raster workflow. By examining common and variant image data color separations, one could identify undesirable images before printing occurred and appropriate revisions in the document or process could be made.
In contrast, vector workflows can allow high resolution rendering to be deferred. This has the benefit of reducing re-processing activities if late changes are made to the original artwork or version documents. However, timely detection of aforementioned version content problems has been less effective in these vector workflows.
Attempts to reduce the occurrence of these problems in the prior art include producing specific types of version documents and using particular processing methods. For example, a version document having common and variant content composed in separate files could be less susceptible to rendering problems if the content was processed separately and the resulting color-separated image data composited (e.g. multiple exposure with different raster) to give an intended result. This solution requires multiple files to be produced and maintained. In contrast, a version document with another composition (e.g. single file) could require that common and variant content be rendered together to produce the image data. Pre-defined rendering rules applied to the painting ordered content elements of a single file could produce undesirable results (e.g. a variant element painting later could unintentionally knock out part of an already painted common element).
However, producing a version document, consisting of a single file comprising common and variant content, is desirable because it is simpler to manage in a workflow. Thus, it is desirable to utilize a single file version document in a vector workflow with the ability to easily check variant content for conditions that could produce an undesirable rendered imaged. Further, it is desirable to be able automatically modify variant content to reduce its potential for producing an undesirable rendered image.